反应详情

To a cooled solution (5° C.) of 5-amino-2-bromo-4-methylbenzoic acid (100.0 g, 0.434 mmol) in anhydrous methanol (1.6 L) was added dropwise thionyl chloride (112.4 g). The reaction mixture was refluxed and monitored by TLC. After refluxing for 6 h, the reaction was complete. The reaction solution was concentrated under reduced pressure. The residue was diluted with ice water (1.2 L) and neutralized with 5% of NaHCO3 to pH 7.5. The aqueous layer was extracted with ethyl acetate (3×600 mL), and the combined organic layers were washed with brine (2×500 mL), and dried over anhydrous Na2SO4. Concentration under reduced pressure provided the title compound as a pale solid. Yield: 99%. 1H NMR (DMSO-d6, 300 MHz): δ 7.25 (s, 1H), 7.14 (s, 1H), 3.30 (s, 3H), 2.15 (s, 3H); MS ESI (m/z) 244 [M+1]+, calc. 243.

1. temperatureThe reaction mixture was refluxed
2. temperatureAfter refluxing for 6 h
3. concentrationThe reaction solution was concentrated under reduced pressure
4. additionThe residue was diluted with ice water (1.2 L)
5. extractionThe aqueous layer was extracted with ethyl acetate (3×600 mL)
6. washthe combined organic layers were washed with brine (2×500 mL)
7. dry with materialdried over anhydrous Na2SO4
8. concentrationConcentration under reduced pressure